The instant invention relates to an open-end spinning machine with a spinning rotor. It has a compressed air conduit directed upon the inner surface of the spinning rotor for the purpose of cleaning it, with the spinning device being closed. It is connected through a stop valve to a source of compressed air. The invention also includes a process to start up such a device.
The feeding of compressed air to the rotor of an open-end spinning device to clean it of deposits and fibers is known in German patents DE 28 11 960 A1 (now U.S. Pat. No. 4,265,083) and DE 27 35 311 A1 (now U.S. Pat. No. 4,211,063). The impurities and fibers loosened by the stream of compressed air are removed by suction.
In another device shown in German Patent DE 27 25 105 A1 (now U.S. Pat. No. 4,178,749) fiber feeding is resumed and stopped before the actual piecing process, in order to remove fibers unsuitable for said piecing process. In this way a fiber tuft of identical nature in quality and quantity is always produced for piecing. To ensure that these fibers, which are temporarily fed into the rotor, are again removed from said spinning rotor reliably, the pressure is maintained beyond this pre-feeding stage until the beginning of the actual piecing process. This pressure can be of only low value, as the fibers would otherwise be prevented, during pre-feeding, from reaching the spinning rotor. This leads to interference in the piecing process. If the pressure is too low, the desired cleaning effect, necessary in order to loosen the impurities, is not attained.